Condensation on outside of air handler

[LSUME05]

I have an air handler installed in the closet, coil below blower. I recently had trouble with water dripping on the floor. The drain was functioning properly, so I cleaned the A-coil and that problem went away. I still don't know where all the water was coming from. Now I have condensation forming on the outside of the unit. I have never noticed this condensation before. We live in south Louisiana and usually keep the t-stat at 73-75 during the day and 69-70 at night. Is this normal?

[stonewallred]

When you cleaned you coil, did you make sure to replace the cover with all the insulation that was on the inside of it?

Is there any air leakage around the cover you removed and replaced in the cleaning?

Both of these could be causing the condensation.

Another question to consider, is the insulation around your suction line all solid with no air gaps or tears, rips or otherwise exposed?

[Special-K]

Reminder

Only Professional Members with an * may give advice in the Ask Or Pros section.

[LSUME05]

I reinstalled the cover just like it was, I didn't remove any insulation.

I don't feel any air leakage around the cover, but some of the condensation is forming along the seam, but most is on the sides.

I'm not sure what you mean by "suction line". The return is in the bottom of the closet door. I sealed the door with weather stripping to force the air through the filter since I noticed a build-up of dust around the door jamb.

[stonewallred]

There should be two copper pipes running to your coil. The big one is the suction line and should be insulated with a black insulation somewhere between rubber and foam.

Is it forming at night or during the day, or all the time?

[LSUME05]

O.K., yes the suction line is fully insulated.

The condensation is forming all the time, but it is worse during the early afternoon.

[stonewallred]

Going out on a limb, but did you clean your coil and weatherstrip the door at roughly the same time?

[LSUME05]

Yeah, it was either the same day, or the next day.

[behappy]

Don't know if I have an * or not but....

Is the "ceiling" top of the AHU closet open to the attic?

[stonewallred]

See if removing the weatherstripping stops the condensation.
If it does, call a reputable contractor out to examine your system for proper amount of return, supplies and operation.
If it doesn't, call a reputable contractor out to examine all of the above.

[LSUME05]

Don't know if I have an * or not but....

Is the "ceiling" top of the AHU closet open to the attic?

It's not open to the attic. There is plywood at the top of the unit, but I don't know how good it is sealed.

[stonewallred]

Unless something changed about his ceiling then it is unrelated to the condensation, IMO.
As it stands we know the OP cleaned his coil and restricted the amount of return air the unit was getting.
He can't easily dirty his coil back up, but he can remove the weatherstripping and see if the restriction of return air caused the condensation.

[LSUME05]

Thanks for the suggestions. I'll remove the weather stripping and see what happens. I'll let you know the outcome.

[heaterman]

Don't know if I have an * or not but....

Is the "ceiling" top of the AHU closet open to the attic?

You do not. Check out the rules at the top of the AOP forums.

[wraujr]

(1) When you added weatherstripping you sealed a major area for air to come in.
(2) The air handler, even when well installed, still has areas where it leaks and wants to draw in air.
(3) With the closet door closed and sealed, air must come from somewhere, second quess would be attic above.
(4) Attic above contains hot humid air
(5) When your air handler/AC is running it gets cool on the cabinet.
(6) Warm, moist air condenses on cool surfaces. Just like when you take a beer out of fridge, you get condensation on the bottle.
(7) If you open the closet door just a crack, you might feel it being pulled closed by the need for air.
(8) If you leave door open, condensation would probably go away.

[energy_rater_La]

is this the first time you have seen condensation on the unit?
plywood @ top of closet can still allow a lot of attic air to
enter unless it is caulked to seal well...